/Engine/Plugins/FX/Niagara/Source/Niagara/Classes/NiagaraScriptSourceBase.h
Adds a module if it isn't already in the graph. If the module isn't found bOutFoundModule will be false. If it is found and it did need to be added, the function returns true. If it already exists, it returns false.
virtual bool AddModuleIfMissing ( [FString](API\Runtime\Core\Containers\FString) ModulePath, [ENiagaraScriptUsage](API\Plugins\Niagara\ENiagaraScriptUsage) Usage, bool & bOutFoundModule )